Tree Are the Champions

At the corner of Bowen Road and Wan Chai Gap Road, you’ll find an absolutely beautiful tree. It sits beside a waterfall and has attached itself to a wall and a bridge. It stretches over 60 feet into the sky. It’s what the Conservancy Association’s environmental affairs officer Martin Wan calls “a giant on the bank.” It is but one example of what is known as a “wall tree,” and a short walk along Bowen Road takes you to several more beautiful specimens.

As the name implies, wall trees are gigantic trees, usually Chinese banyans, that have grown on top of and into masonry walls. The practice of growing trees directly into walls originates with 19th century Guangdong Masonry workers known as the Wu Hua. “The British government had to work on the sloping in Hong Kong in order to get more flatland for development,” Wan says. “In order to do this they built many masonry walls and reclaimed more land for walls and the build-up of Victoria city, which we recognize as Kennedy Town, Wan Chai and Central today.” With the exception of a wall tree in Kowloon Park and a few in Sham Shui Po, they are only found on Hong Kong Island.

Professor C. Y. Jim, chair professor of geography at Hong Kong University, estimates that there are about 1,000 wall trees in the city. “There are 500 stone walls left and about 100 of the wall trees growing on them are particularly beautiful. No other city has so many stone retaining walls and these trees. Forbes Street in Kennedy Town is widely considered to have the best specimen in the city. “It’s the champion of champions,” Jim says. “You have to see it to appreciate its existence. Whenever I take a visitor there, they are amazed. This is nature’s wonderful gift to the city.” Experts believe that there were many more wall trees around the city at one point, but development and a lack of laws steadily eroded their numbers.

Chinese banyan trees are tenacious; they can grow into sheer faces, cracks and stone. “In ecology, this is known as spontaneous growth,” Jim says. “The trees are totally unaided by humans. Birds drop the seeds along the walls and they gradually germinate.” As for the walls, there are generally three layers. The first layer is what we can see. The second layer is rock and sand, which provide the ingredients for the trees to grow. The inner area is made up of big rocks. New walls today, despite artificial stone façades, actually consist of reinforced concrete, which means no new trees will be growing in them.

The same problem that has been steadily whittling down our city’s wall trees continues today; development and a lack of legal protection endanger what Wan calls “our champion trees.” Jim estimates the city has lost hundreds of wall trees over the years. The wall trees on Lung Tue Street nullah in Tai Hang Tung are the latest victims: 20 wall trees grow on both sides of the nullah, which is being covered by the government. “The government has $1.2 billion to cover up nullahs in different parts of Hong Kong. This is a waste of money,” Jim claims. “They think the nullah is no good so they want to cover it up in order to give the impression of continuing development. The blue and green concept of equal planning in Hong Kong has never taken root.”

Also, the stability of the walls themselves is now threatening the trees they support. “Incipient erosion is gradually causing the loss of trees and people are ignoring this,” Jim says. And it doesn’t help that there are only six registered tree doctors in Hong Kong. “We should have as many as possible,” Wan says. “We don’t have enough professional tree doctors to trim and top the trees. Workers cut the trees so badly that they ruin their health. We have to educate more people to learn how to take care of trees.”